The specific aim of this proposed program is to demonstrate the feasibility of using a non-invasive device, a transcutaneous method, for the screening of children and adults for elevated blood lead levels. The proposed instrument: (1) will provide for a rapid and inexpensive test, (2) will eliminate the hazards and problems of blood sampling, and (3) will undoubtedly increase volunteer participation in screening programs--the latter being due to the instruments' portability and benign test protocol. All these factors will significantly contribute to the local health board's ability to achieve the federal guidelines set forth for lead testing by the Center for Disease Control. These attributes will also contribute to a technological innovation which will supercede the conventional screening technique and provide an excellent commercial opportunity. The proposed instrument will utilize the well-established correlation between erythrocyte zinc protoporphyrin fluorescence and possible lead intoxication. The skin surface will be illuminated with blue/violet light and protoporphyrin fluorescence will be detected in the red. A dynamic measure of the quantity of erythrocytes in the observation volume will be provided by other optical techniques. A modest comparison study of this method with conventional lead screening techniques will be conducted in Phase I of the proposed program.